Equivalent tool to Modo tack tool?
Shrinkwrap modifer + Duplifaces

Green cone is instanced while snapped to Suzanne's geometry:




Add a Plane, scale it down in Edit mode to something like 0.01
Add Shrinkwrap modifier to the Plane, switch to Project mode, enable both directions to shrink, set Target mesh and enable Adjust edit cage (all icons near modifier's name)
Add object to be duplicated, parent it to the Plane
In Plane's object settings enable Duplifaces


Now in Edit mode you can start copying Plane (SHIFT-D), move copies and in realtime see result of their placement. If direction of Dupli gone wrong then flip normal of a plane (Edit Mode->W->Flip Normals)